Re: Could not prepare Boot variable

[Roman Riabenko via <help-guix@gnu.org>]

Hello Christophe

On Thu, 09 Jan 2025 20:01:55 +0100
Christophe Pisteur <christophe.pisteur@fsfe.org> wrote:
> Could not prepare Boot variable: No space left on device

I also had this issue recently. The device here is not the boot
partition. Instead, the device here is the EFI itself.

Check whether you have any files begninning with "dump"
in /sys/firmware/efi/efivars/

Those are dump files saved by the pstore kernel module. They should be
safe to remove. Removing them frees up space for a new boot variable.

I do not recommend rebooting until you complete the failed system
reconfiguration. Otherwise, the boot may fail. GRUB did not show up
for me at all.

To prevent dump files from filling up space, I disabled the pstore
backend which saves dump files to efi variables. I added the following
configuration in the operating-system declaration.

  ;; Prevent filling /sys/firmware/efi/efivars/ with dumps
  (kernel-arguments (cons* "efi_pstore.pstore_disable=1"
                           %default-kernel-arguments))

Hope this helps.

Roman